An electronic device that includes a housing and a piezoelectric sensor. The piezoelectric sensor is disposed in contact with an inner wall surface of the housing while in a bent state. The piezoelectric sensor includes a piezoelectric film, a coverlay, a first electrode, a second electrode, a third electrode, and a substrate having flexibility. The first electrode is disposed on a surface of the substrate. The first electrode includes a wide part and a narrow part. The coverlay covers a boundary between the wide part and the narrow part. The piezoelectric film covers a boundary between a part of the first electrode which is covered with the coverlay and a part of the first electrode which is not covered with the coverlay.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A piezoelectric device comprising: a piezoelectric film including a first principal surface and a second principal surface; a substrate having flexibility; a first electrode on the substrate, the first electrode including a first wide part and a first narrow part connected with the first wide part; a covering member covering a first boundary between the first wide part and the first narrow part of the first electrode; a piezoelectric film including a first principal surface and a second principal surface, the first principal surface connected with the first wide part of the first electrode, the piezoelectric film covering a second boundary between a first part of the first electrode which is covered with the covering member and a second part of the first electrode which is not covered with the covering member; and a second electrode connected with the second principal surface of the piezoelectric film.
2. The piezoelectric device according to claim 1 , wherein the piezoelectric film also covers the first boundary.
3. The piezoelectric device according to claim 2 , further comprising a third electrode on the substrate, the third electrode including a second wide part connected with the second electrode, and a second narrow part connected with the second wide part, wherein the covering member covers a third boundary between the second wide part and the second narrow part, and the second electrode covers a fourth boundary between a first part of the third electrode which is covered with the covering member and a second part of the third electrode which is not covered with the covering member.
4. The piezoelectric device according to claim 3 , wherein the second electrode also covers the third boundary.
5. The piezoelectric device according to claim 1 , further comprising a third electrode on the substrate, the third electrode including a second wide part connected with the second electrode, and a second narrow part connected with the second wide part, wherein the covering member covers a third boundary between the second wide part and the second narrow part, and the second electrode covers a fourth boundary between a first part of the third electrode which is covered with the covering member and a second part of the third electrode which is not covered with the covering member.
6. The piezoelectric device according to claim 5 , wherein the second electrode also covers the third boundary.
7. The piezoelectric device according to claim 1 , wherein the covering member comprises one of a PET resin, a polyimide resin, and a resist.
8. The piezoelectric device according to claim 1 , wherein the piezoelectric film comprises poly-L-lactic acid.
9. The piezoelectric device according to claim 1 , wherein the piezoelectric film has an area that is larger than an area of the wide part of the first electrode.
10. An electronic device comprising: a housing; and the piezoelectric device according to claim 1 , wherein the substrate is mounted on an inner wall surface of the housing in a bent state.
11. The electronic device according to claim 10 , wherein the housing is tubular.
12. The electronic device according to claim 9 , wherein the piezoelectric film also covers the first boundary.
13. The electronic device according to claim 12 , further comprising a third electrode on the substrate, the third electrode including a second wide part connected with the second electrode, and a second narrow part connected with the second wide part, wherein the covering member covers a third boundary between the second wide part and the second narrow part, and the second electrode covers a fourth boundary between a first part of the third electrode which is covered with the covering member and a second part of the third electrode which is not covered with the covering member.
14. The electronic device according to claim 13 , wherein the second electrode also covers the third boundary.
15. The electronic device according to claim 9 , further comprising a third electrode on the substrate, the third electrode including a second wide part connected with the second electrode, and a second narrow part connected with the second wide part, wherein the covering member covers a third boundary between the second wide part and the second narrow part, and the second electrode covers a fourth boundary between a first part of the third electrode which is covered with the covering member and a second part of the third electrode which is not covered with the covering member.
16. The electronic device according to claim 15 , wherein the second electrode also covers the third boundary.
17. The electronic device according to claim 9 , wherein the covering member comprises one of a PET resin, a polyimide resin, and a resist.
18. The electronic device according to claim 9 , wherein the piezoelectric film comprises poly-L-lactic acid.
19. The electronic device according to claim 9 , wherein the piezoelectric film has an area that is larger than an area of the wide part of the first electrode.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
September 5, 2017
August 25, 2020
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